The Massachusetts secretary of state is calling out Chief Justice John Roberts over comments he made disparaging the state during the Supreme Court’s oral arguments Wednesday on the Voting Rights Act of 1965.

Roberts, while questioning Solicitor General Donald Verrilli, brought up Massachusetts, a state not covered by the act's preclearance rule, in comparison with Mississippi, which is, as an example of how black voter turnout numbers don’t correlate with the states covered by the provision.

“Do you know which state has the worst ratio of white voter turnout to African-American voter turnout?” Roberts asked, according to the transcript. When Verrilli said he didn’t, Roberts said: “Massachusetts. Do you know what has the best, where African-American turnout actually exceeds white turnout? Mississippi.”

“Which state has the greatest disparity in registration between white and African-American?” Roberts continued, cutting off Verrilli’s response. “Massachusetts. Third is Mississippi, where again the African-American registration rate is higher than the white registration rate.”

The problem, Massachusetts Secretary of State William Galvin says, is that the data does not back up Roberts’s claim.

“It’s just disturbing that the chief justice of the United States would spew this kind of misinformation,” Galvin told POLITICO.

Galvin’s office assumes that Roberts was going off U.S. Census Bureau data, which is one of the only national datasets on voter turnout by race, but they say the 2010 numbers don’t support what Roberts is saying.

“He’s wrong, and in fact what’s truly disturbing is not just the doctrinaire way he presented by the assertion, but when we went searching for an data that could substantiate what he was saying, the only thing we could find was a census survey pulled from 2010 … which speaks of noncitizen blacks,” Galvin said. “We have an immigrant population of black folks and many other folks. Mississippi has no noncitizen blacks, so to reach his conclusion, you have to rely on clearly flawed information.”

The 2010 tables show that Massachusetts does have a high discrepancy between turnout of white and black voters, but is in line with several other states, including Minnesota, Kansas and Washington, which actually has a wider ratio. The states are also similar on registration numbers. Additionally, the margin of error on each of these states’ data is over 10 percentage points, and many states on the list had populations of blacks so small, data wasn’t even available.

“We reached out to academics at many institutions … and they could find no record either, they were puzzled by [Roberts’s] reference,” Galvin said.

Galvin said the only response he’s heard from the court is referring questions to the transcript.

At issue in the case, Shelby County, Ala. v. Holder, is a preclearance requirement of the Voting Rights Act applying to all or most of nine states and parts of seven others, many in the South, which requires all changes in voting districts and procedures to be cleared by the Justice Department or a panel of federal judges. At oral arguments Wednesday, Justices Antonin Scalia, Anthony Kennedy and Samuel Alito all joined Roberts in seeming ready to strike down the requirement, my colleague Josh Gerstein reported. Justice Clarence Thomas, as his custom, did not ask any questions, but is expected to join his conservative fellow justices.

Galvin said it was fair of Roberts to make comparisons between states to which the act applies and to those which it doesn’t, but he said the lack of data to back up his claims was wrong.

“That’s the reason we’re calling him out on it,” Galvin said. “It’s very disrespectful to black voters here in Massachusetts, who do participate in high numbers. It perpetuates the myth that blacks don’t vote. Well they do vote, and they vote very well.”

Galvin said he didn’t know if Roberts’s decision to single out Massachusetts had other motivations.

“I would only note, and maybe this may explain it in some fashion, and I don’t want to do say it does … at least two of the justices on the other side have deep Massachusetts connections: Breyer is a Massachusetts resident and Kagan is the former dean of Harvard Law School, so whether that played into that, I don’t know.”